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0 pointskjeetgill7y ago0 comments

> All of this dates back to design decisions made in the 1990s which presumably seemed reasonable for the time ... Hence, the GIL and the set of tradeoffs it makes. Now, of course, we carry multi-core computers ... Hindsight is great at spotting that, but hindsight doesn't give us a time machine to go back and change the decisions.

Sadly I don't think this is _quite_ true. I believe GILs are used in a number of interpreters and fall prey to the common problem of where either coarsening locks or making them finer ruins somebody's day. I believe Guido Van Rossum hung the GILectomy on two main issues: The interpreter must remain relatively simple, and C extensions cannot be slowed down.

I'm not disagreeing with the decision (necessarily) but it isn't simply a layover from a bygone era. It was a decision that has been reaffirmed and upheld numerous times.

[0]: https://lwn.net/Articles/754577/ [1]: just google Gilectomy, it's been covered in a few places that I don't have handy.

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ubernostrum7y ago

I'm familiar with the various attempts to remove the GIL over the years.

The thing is, in the 90s the choices the produced the GIL as it exists were not bad ones; that's why I went to the trouble of explaining how it affects threaded code and why those effects can be considered reasonable tradeoffs for what was known at the time, in implementing threading (without completely breaking the ecosystem of Python + Python extensions, which was already significant even back then).

Of course, knowing what's known today about the directions computing and the use of Python went in, different decisions might end up being made, but at this point it's very difficult (more difficult than people typically expect) to undo them or make different choices.

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ubernostrum7y ago

I'm familiar with the various attempts to remove the GIL over the years.

j / k navigate · click thread line to collapse